1. Field of the Invention
The present invention relates to control apparatus and method for an internal combustion engine having a variably operated valve mechanism which makes at least one of an operating angle of an intake valve and a valve lift thereof and particularly relates to a technique suitable for a fuel supply cutoff during an engine deceleration.
2. Description of the Related Art
In order to reduce an harmful exhaust emission and to reduce a fuel consumption during a deceleration of the engine, a stop control of a fuel supply or, so-called, a fuel supply cutoff has been carried out during an engine deceleration in which, for example, a throttle valve is fully (completely) closed. In addition, various techniques have been proposed in which a variably operated valve mechanism which enables a valve lift characteristic of an intake valve to be varied is installed and an intake air quantity is adjusted by means of the variably operated valve mechanism and a throttle valve so that improvements of fuel consumption and engine output power are achieved. Two Japanese Patent Application First Publications Heisei 9-250373 published on Sep. 22, 1997 and 2002-089302 published on Mar. 27, 2002 exemplify previously proposed techniques such that the variably operated valve mechanism to vary both of the valve lift of the intake valve and the operating angle of the same is installed and the valve lift and operating angle of the intake valve are controlled to be minimized during the fuel supply cut-off so that a pumping loss is reduced.